U.S. Pat. No. 4,888,988 describes a mass flow sensor which has a thin substrate on which a resistor element is arranged. The thin substrate is secured on a thick, mechanically fixed substrate. The thin substrate is configured as an electrical diaphragm, which is secured on a thick substrate made of silicon. A plurality of resistor elements are arranged on the diaphragm, but none of these resistor elements is arranged such that a rupture of the diaphragm in the stretched area could be detected.